Nonwoven webs are employed in a variety of products including personal care products such as diapers, disposable wipes, tissues, medical fabrics, clothing, and the like. Nonwoven webs which impede the passage of bacteria and other contaminants and have a desirable woven cloth-like hand are particularly desirable.
A barrier impervious to bacterial or other contaminants in a composite nonwoven fabric is often achieved by including a fibrous web, such as a meltblown web of microfine fibers, as a component of a nonwoven fabric. However, bonding such fibrous webs in a nonwoven fabric sufficiently to secure the fibrous layer can destroy or diminish the barrier properties of the fibrous web, particularly where the polymer compositions of the webs differ. Further, bonding such fibrous webs can also diminish fabric drapeability and air permeability. For example, as the percentage bonding area increases in thermal bonding techniques, typically the fabric becomes stiff and the passage of air through the fabric is restricted. Thus minimum bonding area is used in the construction of composite fabrics in an attempt to maintain the barrier properties and maximize fabric drapeability and air permeability of the nonwoven web in the composite.
Nonwoven fabrics having fluid repellent characteristics are particularly desirable for various uses, including use in the manufacture of surgical items such as surgical drapes and surgical gowns and as a component of a personal care fabrics. For example, it is often desirable to incorporate a hydrophobic nonwoven web as a liquid impermeable layer in a nonwoven composite to prevent fluids from penetrating the nonwoven fabric and reaching the wearer's skin. However, material used to manufacture such webs typically have a poor hand or feel, and thus such webs suffer from poor fabric aesthetics. Therefore, it would also be desirable to provide a comfortable texture and absorbency characteristic to a fluid repellent fabric, particularly for a side of a fabric adjacent to the wearer's skin.
U.S. Pat. No. 4,196,245 describes a composite nonwoven fabric which comprises at least two hydrophobic plies of microfine fibers and at least one nonwoven cover ply. The plies are bonded along the edges of the composite fabric to minimize bonding area, presumably to maximize barrier properties of the multiple interior plies. Additionally, multiple interior plies of meltblown webs are required to further provide barrier characteristics.
Others have taught other variations of nonwoven fabrics with various characteristics. U.S. Pat. No. 4,863,785 discloses a nonwoven continuously bonded trilaminate with areas of heavy, intermediate, and light bonding and comprising a meltblown fabric layer sandwiched between two pre-bonded, spunbonded reenforcing fabric layers. U.S. Pat. No. 4,726,976 discloses a nonwoven composite substrate having a fiber-film-fiber structure, the inner layer of which is melted in discrete areas to secure the layers to each other. While the patents disclose various embodiments of nonwoven fabrics, none of these patents disclose a composite nonwoven fabric that provides a barrier to the transmission of contaminants and repel fluids, and yet is also absorbent, has a cloth-like feel, is air permeable or breathable and is bonded to securely stabilize the barrier layer composite within the fabric without losing the benefit of barrier properties. Moreover, despite the widespread use of nonwoven fabrics, many commercially available fabrics still suffer from various shortcomings, such as the diminishment of barrier characteristics and undesirable hand and/or softness.